JPS6290220A - Sealing cover made of plastic welded and fixed to vessel made of plastic and forming method and forming device thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a plastic container for a plastic container, which is made of a plastic material having a different hardness or melting temperature from the plastic material of the sealing lid, and has a neck into which the sealing edge of the sealing lid is inserted. Regarding the manufactured airtight lid.

This type of sealing lid is well known and is generally inserted into the neck of a plastic container, which is usually cylindrical and has a tube-shaped opening, with some error in fitting accuracy. The plastic containers described herein are mainly known as containers for motor oil, and are also used as containers for edible and beverage liquids (edible oil, vinegar, alcoholic beverages, etc.) and various liquid chemical products. is also known.

Because the dimensional stability of the necks of such plastic containers is not very high, and because the shape of the neck is prone to deformation and irregularities during container manufacturing, such necks must be fitted with a liquid-tight plastic seal. To securely attach the lid,
At present, it is necessary to adopt a relatively expensive sealing lid structure. A sealing rim, usually ring- or annular-shaped and having a series of parallel-stacked blades on the outside, projects deeply into the container neck; It is brought into contact with the wall surface to create a seal.

Furthermore, a web or disc-like piece, also ring-shaped or annular, is provided at the sealing edge below the vane, and this web or disc-like piece is engaged with the container wall below the neck, thereby forming a sealing lid. There are also many examples in which the container is configured to be fixed to the container.

In many cases, the sealing lid is provided with a bellows-like corrugation that connects at one end to the sealing edge and extends into the spout piece at the other end. If the material of the sealing lid is sufficiently flexible, the corrugations can be deformed to press a spout piece of smaller diameter than the sealing edge into the neck of the container, and then press it into the neck of the container. It is possible to prevent it from projecting upwardly and outwardly from the top end. A tear ring is provided at the upper end of the spout piece,
This allows the spout piece to be pulled out of the neck of the container when necessary.

Some of the above-mentioned known side sealing lids have drawbacks that cannot be ignored. For example, a sealing lid made of a plastic material with varying degrees of elasticity can be inserted between the neck of the container and the sealing edge of the lid using an appropriate tool such as a screwdriver. It can be removed from the container using a lever. However, since no trace of the lid typically remains after its removal, and because the lid can be reinserted into the neck of the container, the correct lid and container combination may be unknown. Moreover, the tightness of the lid can only be guaranteed if the neck is manufactured with a relatively high degree of precision, and for this reason it is not possible to use very round-the-wheel methods. Another disadvantage is that a relatively large amount of plastic material is required for the long projecting sealing edge into the container, for the laminated wings and for the fastening webs or discs. Another problem is that the molding of the sealing edge and adjacent sealing and fixing pieces requires relatively high equipment costs, which contributes to a significant increase in manufacturing costs.

Therefore, an object of the present invention is to be able to manufacture the container neck without requiring a large cost for manufacturing equipment, to be able to manufacture the container neck easily, and to use a relatively small amount of raw materials or materials. To provide a plastic airtight lid for a plastic container, which can be securely fixed to the neck of a plastic container and which does not come off the container unless the lid itself or the container is destroyed.

This problem is solved according to the invention by making the end face of the sealing edge substantially adjoin the end face of the container neck and by welding the sealing edge to the neck by simultaneously heating adjacent end faces.

The end surfaces of the sealing rim and the container neck are preferably formed adjacently and in the same plane before welding, so that a single surface with a flat welded surface is formed. Both can be easily processed simultaneously with one welding tool.

If these end faces can be heated simultaneously using appropriately shaped welding tools, and if it is possible for two types of plastic materials with different hardnesses or melting temperatures to melt and flow into each other, They may be in virtually any angular configuration with respect to each other. This fluidization treatment of the plastic material may be made easier by providing a gap of an appropriate width between the two end faces to be welded.

By the description "simultaneously heated", the applicant means that the moment when two plastic materials to be welded together, if possible, reach their respective melting or melting temperatures simultaneously and are liquefied. It means to allow one to flow into the other. For this purpose, the heating of the plastic material with a higher melting temperature should be started slightly earlier than the heating of the plastic material with a lower melting temperature, otherwise the heating process would start at the same time, but the heating of the plastic material with a higher melting temperature It would be necessary to apply more heat to the lower plastic material than to the lower plastic material.

Of the above two heating methods, the former involves placing the two end faces made of different plastic materials parallel to each other but slightly offset from a common plane, and comparing the end faces made of the plastic material with the lower melting temperature. This can be facilitated by arranging the end face of the higher plastic material to be slightly protruding and thus to contact the flat welding surface of the welding tool slightly earlier.

A method of forming a plastic sealing lid according to the present invention will be described in more detail below.

According to the invention, the closure lid is welded to the neck of the container, which is advantageous from various points of view. The dimensional stability of the container neck and the sealing edge of the closure lid is achieved by placing the parts to be welded sufficiently close to each other, a method that could not be achieved automatically in conventional mass production methods. The degree of demand for is reduced. The relatively high expense required for molding laminated wings and fastening pieces on the sealing edge can be avoided. Moreover, the welded fixation provides for the formation of a completely liquid-tight closure, which will not come loose from the container unless there is obvious damage or destruction.

The method of forming a plastic sealing lid according to the invention, which can be carried out at low cost and is economical in terms of plastic material consumption, is a mass-produced product and can be sold in very large quantities and used in various suitable containers. It is particularly advantageous in the production of attached closures. According to the invention, the neck of the container and the sealing edge of the lid are formed substantially cylindrical, which also facilitates their manufacture and handling.

In the plastic sealing lid according to the present invention, a flange portion is formed on the sealing edge thereof to protrude or extend, and the flange portion is disposed on the end face of the container neck portion. According to this, when the sealing lid is inserted into the opening of the container neck, its position is substantially fixed, and therefore the welding process can be performed without the need to take the trouble of adjusting the position of the lid. becomes possible.

Furthermore, with respect to the closure according to the invention, the flange-like edge of the container neck is in the form of a flange with upright webs at the ends, which have a height equal to the wall thickness of the protruding or extended flange of the closure. It is particularly advantageous to form the closure with an upright projecting portion and an inner dimension or diameter smaller than the outer dimension or diameter of the projecting or extending flange. , the annular flange of the sealing edge overlaps the flange-like edge of the container neck, and the annular flange is surrounded at its periphery by and fits into the upright web of the container neck. At the same time, the height of the upright protruding portion of the upright web portion is such that the top surface of the portion is flush with the top surface of the protruding or extended flange portion of the closure, and The top end surface of the upright web portion is formed to be substantially contiguous with and coplanar with that of the flange portion of the closure lid.

By configuring the end faces of the sealing lid and the container neck as described above, it is possible to easily approach them with appropriate welding processing means, and to do so safely and reliably.

Relating to a method of manufacturing or forming a plastic sealing lid for a plastic container, which is manufactured from a plastic material having a different hardness or melting temperature than the plastic material of the sealing lid, and having a neck into which the sealing edge of the sealing lid is inserted; An object of the present invention is to heat at least one portion of the end face of the sealing edge of the adjacent sealing lid and the end face of the container neck to a temperature slightly higher than the melting temperature of the respective plastic materials of the sealing lid and the container. Solved by heating at the same time.

Simultaneous heating of two plastic materials of different hardness and/or melting temperature causes them to liquefy and flow into each other, thereby forming a strong, liquid-tight seam or joint. Methods of welding plastic materials together by simultaneously heating each part to be welded are known, but these known methods relate to welding plastic materials having substantially the same hardness and/or melting temperature. . Plastic materials with different melting or melting temperatures are joined together by liquefying the lower temperature plastic material and adhering it to the higher temperature plastic material, which remains solid. Methods are also known. However, the effectiveness of this type of adhesive joint is not very strong and can easily come apart when the tear ring attached to it in one embodiment of the closure lid is pulled out.

According to the method of the invention, it is also possible to simultaneously heat the adjacent end faces of the sealing edge and neck on both sides of their parting line and over their entire circumference to a temperature slightly above the melting temperature of the respective plastic material. It will be done.

With this method, a completely liquid-tight fixed attachment of the closure lid to the container is achieved in only a short time and with a single welding operation.

An object of the present invention is to provide an apparatus for carrying out the method for producing or forming a sealing lid as described above, and an object of the present invention is to provide a welded (processed) member with at least the end face of the sealing edge of the sealing lid to be welded and that of the container neck. The solution is to provide welded surfaces that are parallel and movable to contact the end faces.

A welding element is brought into contact with the end surfaces of the sealing edge and neck to heat the end surfaces and cause them to liquefy and flow into each other to form a seam or joint. Since the welding process or working surface of the welding part is brought into contact with each of the end faces at the same time, the plastic material with the lower melting temperature starts to flow first, but the welding part is still in a solid state at this time. As long as it is supported on the hotter end face of plastic material, it can be imagined that contact with the hot welding work surface is lost.

This method prevents overheating and decomposition of the plastic material with a lower melting temperature. As soon as the plastic material with a higher melting temperature is fluidized, the two plastic materials flow into each other to form a joint.

Depending on the nature, flow characteristics, and density of the plastic materials to be welded together, the gap maintained between the welded parts along the parting line until welding is performed will provide the most favorable mixing of the fluidized plastic materials. They may be of various widths, depths, and/or sloped configurations to achieve the desired results.

In order to make the seam or welded part as aesthetically pleasing and uniform as possible, according to the invention it is also possible to use an anvil as a support member for the welding member that is brought into pressure contact with the end face to be welded. However, the availability of this anvil and the method of its installation will vary depending on the shape of the closure and container neck and the location of the welds or joints.

The neck of the container has a flange-like edge with an upright web portion at the end, and the sealing edge of the closure lid has a protruding or extending flange portion flush with the upright protruding portion of the web portion. In the case of an embodiment of the plastic closure according to the invention, it is advantageous and advantageous for the welding member to be in the form of a hollow cylinder and the anvil to be in the form of a split ring.

The outer dimension or outer diameter of the hollow cylindrical welding member is smaller than the inner dimension or inner diameter of the annular protrusion or extension flange of the sealing lid, and the inner dimension or inner diameter is smaller than the inner dimension or inner diameter of the annular flange-like edge of the container neck. It shall be larger than the inside dimension or inside diameter.

According to this, it is possible to ensure that the welding process or working surface of the welding member engages with the end face of the flange portion of the adjacent sealing lid and that of the flange-like edge of the container neck on both sides of the parting line or gap. , a complete annular weld can be formed.

It is also preferred that the hollow cylindrical welding member has an inner diameter larger than that of the protruding or extended flange and an outer diameter smaller than that of the flange-like edge. In this case, a small part of the end face of the plastic material to be welded (i.e. the flange of the closure lid and the flange-like edge of the container neck) is located inside and/or outside of the hollow cylindrical welding part. This prevents the liquefied plastic from flowing out laterally.

Another feature of the present invention is that the welding member can be heated from its outer periphery by a heating coil.

Heating from the outer periphery creates a radial temperature gradient on the surface of the welding member. According to this configuration, for example, an upright web of plastic material with a higher melting temperature located on the outermost side of the edge of the container neck is joined to a plastic material with a lower melting temperature located on the inner part of the welding working surface. This results in a larger amount of heat being applied to the flange of the sealing lid made of wood. This has the effect of hastening the liquefaction and mixing of the two plastic materials and thus speeding up the welding operation as a whole. If the plastic material with a higher melting temperature is on the inside of the welding member, a heating coil equivalent to that provided above should be provided on the outer periphery of the hollow cylindrical or other shaped welding member. Of course, it is also possible.

In a particularly preferred embodiment of the invention, the welding member is an ultrasonic welding head.

The ultrasonic welding method itself is well known. Ultrasonic welding head
Transmits ultrasonic vibrations to the object to be heated or welded. If the ultrasound is powerful enough, a large amount of energy will be absorbed in the fusion zone in the plastic material and converted into thermal energy by inelastic action and friction, thus starting to melt or melt the plastic material. The advantage of ultrasonic waves is that they can be emitted in a directional manner, so that they can be carefully heated inside the plastic material to be welded. Therefore, the effect of heating is not only superficial but also deep. This speeds up the welding operation and achieves a deeper and more favorable joint.

When the plastic material liquefies, so that it is no longer in contact with the ultrasonic welding head, the heat supply is rapidly cut off. Therefore, the heat applied to the plastic material is controlled automatically by changes in the plastic material. As mentioned above, it is also advantageous to have a configuration that creates a temperature gradient.

Other structural features, effects, and uses of the present invention other than those described above will become apparent from the following description of preferred embodiments of the present invention with reference to the drawings.

1 and 3a to 3c show in cross-section one embodiment of a plastic closure for a plastic container according to the invention.

The neck 2 of the plastics container (or simply container) 5 has a flange-like edge 8 at its top end with an upright web 6 formed therein. The height of the upright protruding portion of the upright web portion 6 is determined by the wall thickness (or height) of the protruding or extended flange portion (hereinafter simply referred to as flange portion) 7 of the sealing edge 1 of the sealing lid (or simply referred to as the lid). ), so that the top end face 3 of the flange portion 7 and the top end face 4 of the upright web portion 6 are equal to
are adjacent to each other in a common plane and substantially contiguous with each other. The sealing edge 1 is connected with a hollow corrugated portion 16 that allows insertion of the lid. The other end of the corrugated portion 16, which is connected at one end to the sealing edge 1, extends to a threaded spout piece 12, which is fitted with a threaded cap. 13 is screwed in. The spout piece 12 is also secured by a sealing membrane 14. Also shown in FIG. 1 is a tear ring 17 which allows the spout piece 12 connected to the sealing edge 1 via the corrugations 16 to be pulled out of the neck 2. It is.

Between the outer side end face of the flange part 7 and the inner side end face of the upright web part 6 there is a narrow gap 15', shown as parting line 15 in FIG. 2a. This gap 1
The width of 5' is adjusted and set so as not to cause trouble when the plastic material liquefies. It is also possible, in the cross-section of FIG. 3a, for the vertical gap 15' to be inclined. Therefore, the flange portion 7 and the upright web portion 6 do not necessarily have to be at right-angled corners.

In addition to the sealing lid, FIG. 3b also shows in cross-section the welding element 9 and the anvil 11 which serves as its support or brace.

In this embodiment of the invention, the welding member 9 is of hollow cylindrical shape and its diameter and wall thickness are such that the welding or working surface of this member covers the end faces 3 and 4 on both sides of the gap 15'. , it is possible to cover a wide area and the entire circumference of the sealing lid, although not completely.

FIG. 3b also shows in cross section the heating coil 18 which generates a temperature gradient in the radial direction of the welding element 9.

Figure 3b shows the closure just before the welding operation is performed. When the welding member 9 consisting of an ultrasonic welding head is lowered onto the end faces 3 and 4, the flange portion 7 of the sealing edge 1 (
(assumed to be made of a plastic material with a lower melting temperature) begins to melt and its degree of contact with the welding element 9 gradually decreases, thus avoiding further heating of the liquefied plastic. However, at the same time, the upright web part 6 is maintained at its I end in contact with the welding part 9 and is thus heated to its melting temperature and finally becomes liquid and mixes with the liquefied plastic of the flange part 7. Ru.

The weld or joint 10 thus formed is the third C.
As shown in the figure. In this state, the sealing edge 1 is completely liquid-tight and securely inserted into the container 5 via the upright web part 6.
It is joined to the neck part 2 of. The strength of the joint or joint 10 is exactly the same as that of the plastic material of the container and closure.

According to this embodiment of the invention, the amount of plastic material required for the manufacture of the sealing edge 1 and thus also of the sealing lid as a whole is reduced in the case of known sealing lids with laminated air sealing wings and fastening pieces. Only a small amount is required compared to .

FIG. 4a shows, in cross-section, a container neck and an associated closure lid according to another embodiment of the invention. Only the sealing edge 1 of the sealing lid is shown. In this embodiment, the neck 2 of the plastic container 5 is round-shaped, as is the sealing edge of the closure lid. This embodiment is particularly easy to implement and economical in terms of plastic material usage. The conical (or inverted conical) shape of the neck 2 provides a convenient fixed seat for the sealing edge 1. Even if there is an overlapping portion between the neck and the end face of the lid, such portion can be melted and lost by the welding member 9. FIGS. 4A and 4C show the state immediately before and after the welding operation, respectively, similarly to FIGS. 3b and 3c, respectively.

FIG. 5a shows yet another embodiment of the invention; FIG.
This is a sectional view similar to that shown in FIG. 2, and the shape of the neck portion 2 is also very simple in this embodiment. The sealing edge l has a flange portion 7 that projects or extends on the top end surface of the neck portion 2, and has a lateral end surface 3 of this flange portion 7.
' and the lateral end surface 4' of the neck 2 form substantially contiguous adjacent end surfaces. Therefore, the welding member 9 is adapted to perform a movement toward the container and the sealing lid from the side.

However, in the case of this embodiment, a plurality of arc-shaped welding members 9 are required in the plan view, and it is virtually impossible to move them concentrically, so welding is performed in one step. is not possible. In order to perform welding without discontinuities or completely circumferentially, a plurality of arc-shaped welding members 9 in plan view are arranged in pairs, for example in a cross or star shape, and these are welded two or more times. Make it work.

Figures 5A and 5C show the welding operation immediately before and after the welding operation, respectively. Figures 2a and 2b are plan views showing the joints in the embodiments shown in Figures 1 and 3a to 3c. It is shown that the joint 10 has a kind of pattern. This pattern results from the pressure exerted by the welding work surface of the ultrasonic welding head; The contact work surface is provided with a pattern or irregularities to improve the heating effect. However, if the welding element is not an ultrasonic welding head, but a heating element commonly used in the past, it is also possible to carry out the operation in such a way that a completely smooth welding surface is obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a preferred embodiment of a plastic closure inserted into the neck of a plastic container. FIG. 2a is a plan view of FIG. 1, showing the state before welding work. Figure 2b shows the state after the welding operation, the first
FIG. FIG. 3a is an enlarged partial cross-sectional view showing a portion of FIG. 1 on an enlarged scale. Figures 3b and 3c are enlarged partial sectional views of the same portion as Figure 3a, showing the state before and after the welding operation, respectively. FIG. 4a1 is a schematic cross-sectional view showing only the sealing edge of the sealing lid, showing another embodiment of the present invention. 1A and 4C are enlarged partial sectional views corresponding to FIGS. 3b and 3C, respectively, showing the embodiment of FIG. 4a. 5a to 5c are sectional views similar to FIGS. 4a to 4c, respectively, showing still other embodiments of the present invention. FIG. 6 is a perspective view showing a preferred embodiment of the welding means (/8 contact member and anvil). ■... Sealing edge, 2... Neck, 3, 4... (Top end) end surface, 3', 4'... (Side end) End surface, 5.
...Plastic container, 6...Upright web part, 7.
...(protrusion or extension) flange part, 8...flange-like edge, 9.9'...welding member (ultrasonic welding head)
, 11...anvil, 15...dividing line, 1st...
heating coil.

Claims (1)

[Claims] 1. The plastic material of the sealing lid is made of plastic materials with different hardness or melting temperature, and the sealing edge (1
) with a neck (2) into which the plastic container (
5) is a sealing lid welded and fixed to the sealing edge (
The end faces (3, 3') of 1) are the end faces (4, 3') of the neck (2).
4'), and this sealing edge (1) simultaneously heats the substantially adjoining end faces (3, 4) (3', 4'). A plastic sealing lid, characterized in that it is welded to the neck (2). 2. The neck (2) of the container (5) and the sealing edge (
A plastic sealing lid according to claim 1, characterized in that 1) has a substantially cylindrical shape. 3. Patent characterized in that said sealing edge (1) has a protruding or extending flange (7) located on the end face (4) of the flanged edge (8) of said neck (2) A plastic sealing lid according to claim 1 or 2. 4. Said flange-like edge (8) has an upright web portion (
6) in the form of a flange with an upright projecting portion of a height equal to the wall thickness of said projecting or extending flange portion (7) and greater than the outer dimensions of said projecting or extending flange portion (7). 4. Plastic sealing lid according to claim 3, characterized in that the lid also has small internal dimensions. 5. Made of plastic material, the sealing edge of the sealing lid (1
) with a neck (2) into which the plastic container (
5), the plastic material of the upper neck (2) is manufactured from a plastic material having a different hardness or melting temperature, and the end surfaces (3, 3') of the sealing edge (1) are the end surfaces of the neck (2). (4, 4') by welding and fixing a sealing lid formed so as to be substantially connected to the end faces (3, 3') and neck of the sealing edge (1). (2) At least a portion of each of the substantially contiguous end surfaces (4, 4') of the plastic material is simultaneously heated to a temperature slightly exceeding the melting temperature of each of the plastic materials. How to form an airtight lid. 6. Adjacent end surfaces (3, 4) of the sealing edge (1) and neck (2) are simultaneously coated with each of the plastic materials on both sides of their parting line (15) over their entire circumference. 6. The method of forming a plastic sealing lid according to claim 5, wherein the method comprises heating to a temperature slightly higher than the melting temperature. 7. Made of plastic material, the sealing edge of the sealing lid (1
) with a neck (2) into which the plastic container (
5) a plastic sealing lid configured such that the end faces (3, 3') of the sealing edge (1) are substantially connected to the end faces (4, 4') of the neck (2); The device is formed by welding and fixing the sealing edge (1) and the neck (2) to substantially connected end surfaces (3, 4) (3', 4).
Apparatus for forming a plastic sealing lid, characterized in that it has welding members (9, 9') with welding surfaces that are parallel to and movable in contact with their end faces. 8. The welding member (9) brought into pressure contact with the end surfaces (3, 4)
, 9') has an anvil (11) as a support member for the plastic sealing lid according to claim 7. 9. Formation of a plastic sealing lid according to claim 7, wherein the welding member (9) is a cylindrical member, and the anvil (11) is a split ring-shaped member. Device. 10. A heating coil (18) on the outer periphery of the welding member (9)
Claims 7 and 8 are characterized in that
The apparatus for forming a plastic airtight lid according to item 1 or item 9. 11. The apparatus for forming a plastic sealing lid according to claim 7, 8, 9 or 10, wherein the welding member (9) is an ultrasonic welding head.